The Human Biological Sampling and Immunocytometry core will provide essential clinical and immunological support for both projects in this proposal. The core encompasses personnel with appropriate technical expertise to accomplish the proposed studies, and the resources/facilities with which to do so. Vital to the entire program project is obtaining human samples for experimentation, which is the first of three functions of the core. Along with participant recruitment, and obtaining specimens, the Subject Recruitment and Biological Sampling component of the core will oversee efficient distribution of cells to the appropriate laboratories. Two additional components of the core, the Cellular Processing component and the Flow Cytometry component, are aimed at preparing samples for proposed experiments and in some cases performing data acquisition and analysis. Each of these two components will be involved in setting up initial BAL cell and airway epithelial cell cultures, as well as data acquisition and analysis for certain aspects of both projects. The specific aims for the proposed core are as follows: Aim 1: Subject Recruitment and Biological Sampling. This component will help to recruit healthy controls and asthmatics of varying severity and obtain biological specimens. In addition, the core will oversee efficient distribution of cells to the appropriate laboratories. Aim 2: Cellular Processing. This component is aimed at preparing samples for the proposed experiments in the two projects and Core C. Aim 3: Flow Cytometry. In this component, the core will work with investigators to provide immunophenotyping of cells via staining with labeled antibodies. In addition, the core will assist investigators with performance of high-yield, high-purity cell sorts to provide material from human blood and BAL fluid for further experimentation.